Say I want 4 gigs of ram, would it be better to get (2) 2 x 4 or (4) 2 x 4 sticks. Are there any performance differences between the two?

I'm not sure exactly what you mean, but to my knowledge if you have a combination of any speed or grouping it runs the same. What does matter though is the version of windows that you're using. XP x32 has a max of 3.5 gigs of ram.

jwenham,If you are planning on overclocking, you are best off getting 4GB in a 2x2GB kit. You will have a much harder time trying to overclock four 1GB modules. Also, it is possible the motherboard could limit your maximum memory speed when all four slots are populated.